external image 361px-Full_length_hammerhead_ribozyme.png

RNA


RNA (ribonucleic acid) is a nucleic acid similar to DNA. It is a single stranded chain of nucleotides that contains genetic information. It is used to send messages with the coded nucleotides to other parts of the cell, instructing cell functions such as protein synthesis in the ribosome. Each nucleotide is made up of adenine, cytocine, guanine, and uracil (A, C, G, U) which makes up the coding on the RNA strand. Note the Thymine is replaced by the Uracil when RNA is transcripted. Each one corresponds to the other half of the strand, the DNA, which the RNA splits from during transcription. When this messenger RNA reaches a ribosome, translation takes place, where the ribosome uses the code to make certain amino acids.

Responsible for the movement of genetic information from the DNA in the nucleus to the site of Protein synthesis in the cytosol
Structure of RNA:
Single-stranded nucleic acid made up of repeating units, like DNA
Sugar molecule is RIBOSE (not deoxyribose)
Thymine is replaced with URACIL (U)

external image mRNA-colored.gif
Messenger RNA (mRNA): RNA that is a template to make proteins in the ribosome. Nucleotides in a single uncoiled chain that carries genetic information from nucleus to the ribosome.

Ribosomal RNA (rRNA): Attaches to mRNA to hold it together during translation. Nucleotides in a globular form.

Transfer RNA (tRNA): reads the mRNA codons using "anticodons". Nucleotides in a cloverfeaf chain.

Codon: a group of 3 Bases that create one amino acid during translation.

See animation of a RNA strand being translated at http://catalog.nucleusinc.com/generateexhibit.php?ID=18654&ExhibitKeywordsRaw=&TL=&A=2

See video and interactive activites at http://nobel.scas.bcit.ca/resource/dna/station2.htm#
external image RNA_sstrand.jpgRNA is a DNA strand torn in half during transcription.
RNA
Similar
DNA
Single strand
A, C, G, U
Contains Ribose
Moves genetic information
Both nucleaic acids
Both contain genetic information
Use combination of 4 nucleotides
Double strand
A, C, G, T
Contains Dexyribose
Stores genetic information